MAXIFY GX7021 image defect

[pcwizard]

One of our customers has a Maxify GX7021. They recently started having image defects as shown in the attached test page sample. Nozzle cleanings have been done, alignments done, roller cleaning and bottom plate cleanings done. Visual inspection shows internals relatively clean. Set it up with a different computer, same results. The defects are random on the page. Any thoughts ??  Thanks.....